1. Technical Field
The present disclosure relates to a control power supply device for an inverter. More particularly, the present disclosure relates to a control power supply device for an inverter, which senses an output voltage of a main switched-mode power supply (SMPS) for supplying stable power to the inverter, and, if the sensed voltage is not in a normal range, interrupts an operation of the main SMPS to operate an auxiliary SMPS, and transmits trip information to a controller for controlling the inverter.
2. Description of the Related Art
An inverter is a power conversion device that converts AC mains electricity to a DC voltage and then again converts the DC voltage to an AC voltage, thereby freely controlling an electric motor.
Inverters find a variety of applications in the overall industry, including fans, pumps, elevators, transfer devices, production lines, and the like. Typically, an inverter for driving motors converts power in such a manner that it receives and converts three-phase AC mains electricity to a DC voltage using a rectifier circuit, stores the DC voltage in a capacitor of a DC-link, and then converts the DC voltage to an AC voltage using an inverter unit.
An inverter is a variable voltage variable frequency (VVVF) system, whose voltage and frequency input to an AC motor can vary depending on a pulse width modulation (PWM) output, thereby controlling the speed of the motor.
Typically, inverters or converters as power conversion devices essentially includes auxiliary circuits for performing functions including communications, protection, control, and the like, as well as a circuit for performing a main function. Such auxiliary circuits require the respective stable rated voltages to be supplied thereto. To this end, a switched-mode power supply (SMPS) is employed. If a problem occurs in an operation of the SMPS, it also affects the main function of the inverter. Hence, the SMPS is an especially important component among others.
The SMPS is a very important circuit that supplies power to a controller for controlling the overall operations of the inverter and other main functional circuits. If a problem occurs in the stable power supply of the SMPS, functions of the controller and the main functional circuits are interrupted, which actually results in interruption of the overall functions of the inverter. In existing inverters, an SMPS is a sole component as a main circuit of the inverter and thus is highly risky and the inverter is not highly reliable.
In practice, from analysis results of the field claims on the existing products, it can be seen that the failure that the SMPS does not work appears at high rate.